WaterVerge

Is Sauk, IL Tap Water Safe to Drink?

Graded D — but Strontium, 1,4-Dioxane and 1 more were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

10K residents served 2 water systems PWSID: IL0312790
Overall Score
46 / 100
Violations
43 active
Last Updated
May 2026
Source
Groundwater
#862 of 891 in Illinois Top 89% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
DGRADE
Water Quality Grade
46/100
waterverge.com
D 46/100

Sauk, IL — Water Quality Report

Sauk's drinking water received a grade of D (46 out of 100), indicating poor water quality. The city's 2 water systems serve approximately 10,142 residents using groundwater.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 196 violations on record, including 5 health-based violations. 43 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Sauk's water

Sauk ranks #862 out of 891 cities in Illinois for water quality, placing it among the lowest-rated in the state.

Sauk relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

The system has seen 104 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
46 out of 100 Grade D
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
0/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
15.9/20
B
1 PFAS compound detected.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Sauk, IL water safe to drink?

Concerns Identified

Sauk's drinking water has significant quality concerns based on EPA testing data. With a grade of D (46/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 10,142 residents using groundwater (wells).

43
Active Violations
0.0 ppb
Lead (90th %ile)
1 compound
PFAS Detected
9 events
Disaster History

Recent water quality updates for Sauk

A timeline of significant water quality events, violations, and data updates.

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Sauk's water quality assessment. Grade: D (46/100).

Violation
5 drinking water violations recorded

Contaminants: Public Notice, Consumer Confidence Rule.

Disaster
SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODNG

Federal disaster declaration (FEMA DR-4819). Flood event — may have impacted local water infrastructure.

Violation
1 drinking water violation recorded

Contaminants: Consumer Confidence Rule.

Violation
42 drinking water violations recorded

Contaminants: Vinyl chloride, 1,2,4-Trichlorobenzene, cis-1,2-Dichloroethylene.

Key contaminant findings

Based on the most recent EPA sampling data for Sauk's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 70.3000 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

Violation history

Sauk's water system has 196 total violations on record, including 5 health-based violations. 43 remain unresolved. 104 violations were issued in the last 5 years.

OtherMRMCL
Most recent violations:
Jul 2025 Public Notice Open
Jul 2025 Public Notice Open
Jul 2025 Public Notice Open
Jul 2025 Public Notice Open
Jul 2025 Consumer Confidence Rule Open

Flood & environmental risk

Cook County has experienced 9 federally declared disasters since 1972. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Turkey Creek, Little Calumet River, Plum Creek, Hart Ditch, Little Calumet R.

SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODNG
Flood FEMA DR-4819
SEVERE STORMS AND FLOODING
Flood FEMA DR-4749
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA DR-4116

Where does Sauk's water come from?

Sauk's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 10,142 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Turkey Creek (river), Little Calumet River (river), Plum Creek (river), Hart Ditch (stream), Little Calumet R (river).

What Sauk residents can do

Install a water filter

Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Sauk's water.

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Monitor alerts during storms

Sauk's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
70.3000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
Strontium
Inorganic
Over HRL
1697.2 µg/L
EPA Health Ref Level: 1,500 µg/L · +13% over limit
Over HRLUCMR 3 Data
1,4-Dioxane
Organic
Over HA
1.46 µg/L
EPA Health Advisory: 0.35 µg/L · +20% over limit
Over Health AdvisoryUCMR 3 Data
Manganese
Inorganic
Over SMCL
60.0 µg/L
EPA Secondary MCL: 50 µg/L · +20% over limit
Over SMCLUCMR 4 Data
Molybdenum
Inorganic
Detected
9.40 µg/L
EPA Lifetime HA: 40 µg/L · 24% of limit
DetectedUCMR 3 Data
Lithium
Inorganic
Above state screening
70.3 µg/L
State screening level: 60 µg/L · +17% over limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

196
Total violations
5
Health-based
43
Active / unresolved
Jul 2025
Most recent violation
Compliance Record

Violations & advisories

196 Total
43 Active
5 Health-based
153 Resolved
Violations by category
Volatile Organic Chemicals
82
Synthetic Organic Chemicals
58
Public Notice Rule and Revised PN Rule
38
Total Coliform Rule
9
Consumer Confidence Rule
3
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Consumer Confidence Rule
Other Violation 0
Jul 2024 Active
Consumer Confidence Rule
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Feb 2024 Active
Public Notice
Other Violation 0
Showing 20 of 196 violations
Environmental Risk

Flood & disaster history

9
Declared disasters
Sep 2024
Most recent
Flood
Most common type

Cook County has experienced 9 federally declared disasters since 1972. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Sep 2024
SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODNG
Flood FEMA #4819
Nov 2023
SEVERE STORMS AND FLOODING
Flood FEMA #4749
May 2013
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA #4116
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3230
Jul 1993
SEVERE STORMS & FLOODING
Flood FEMA #997
Aug 1987
SEVERE STORMS & FLOODING
Flood FEMA #798

Recommended water filters

Based on contaminants detected in Sauk's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium 70.300 HI µg/L PFAS Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 0.0 ppb from 1992 (0.0 ppb) to 2025 (0.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
10,142
Water Systems
2
Source breakdown
Groundwater
1
Purchased Groundwater
1
Water Source

Where Sauk's water comes from

Groundwater

Sauk's drinking water is drawn from underground aquifers through wells.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.

Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.

The system is operated by local government ownership and serves approximately 10,142 people through 2 water systems.

Local Hydrology

Water bodies near Sauk

Sauk is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

Turkey Creek
river
Little Calumet River
river
Plum Creek
river
Hart Ditch
stream
Little Calumet R
river
Infrastructure

Water systems serving Sauk

System Name PWSID Population Source
SAUK IL0312790 9,921 GW
WEATHERSTONE LAKES MHP IL0312800 221 GWP
Regional Comparison

How Sauk compares

Full Illinois rankings →

Sauk's score of 46/100 is below the average of 56/100 among major Illinois cities. It outscores 5 of 10 nearby cities.

Sauk (this city)
46
Chicago
35.2
Aurora
45.5
Joliet
38.5
Naperville
81.2
Champaign
91.9
Illinois avg
56
City Profile

About Sauk, IL

Wikipedia →

Sauk Village is a village and a south suburb of Chicago in Cook County, Illinois, United States. The population was 9,921 at the 2020 census.

Economic Profile
$50,393
Median Income
$84,139
Median Home Value
$1,433/mo
Median Rent
15.9%
Unemployment
Community
32.6
Median Age
954
People / sq mi
17.6%
College Educated
56.3%
Homeownership
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Frequently asked questions

Is Sauk, IL tap water safe to drink?

Sauk's water quality earned a grade of D (46/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #862 out of 891 cities tested in Illinois.

What contaminants are in Sauk's water?

Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 196 violations are on record.

How is Sauk's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Sauk?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Sauk's water come from?

Sauk's water is sourced from Groundwater. The city has 2 water systems serving approximately 10,142 residents.

What health violations has Sauk's water system had?

Sauk has 5 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 43 violations remain unresolved.

Is Sauk's groundwater at risk of contamination?

Sauk uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 196 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Sauk's water compare to other cities?

Sauk ranks #862 out of 891 cities in Illinois (better than 3% of state cities) and #13936 out of 15744 cities nationally (12th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.